The invention relates to a display device with a display cell which comprises a substrate which is formed by two oppositely located plates whose facing sides are provided with electrode layers to which an orientation layer is applied and a sealing material which is provided between the end portions of the plates, and a liquid crystalline material provided in the space between the plates and the sealing material.
The invention also relates to a method of manufacturing a display device with a display cell which comprises a substrate which is formed by two oppositely located plates whose facing sides are provided with electrode layers to which an orientation layer is applied and a sealing material which is provided between the end portions of the plates, and a liquid crystalline material provided in the space between the plates and the sealing material.
Such a device can be used, for example, in alphanumeric, datagraphic display devices, in particular in passive displays. In such devices at least one of the substrates and the associated electrode layer consist of a transparent material. The other substrate may have a reflective effect or also consists of a transparent material.
A liquid crystal display device comprises a cell having switchable liquid crystalline material between two flat substrates on which electrical conductor tracks and electrodes may be located which can be used to switch the liquid crystalline material between an "on" and an "off" state in accordance with a desired pattern. The electrode layers consist of material which is transparent to visible light, for example tin oxide and/or indium oxide. To provide the molecules of the liquid crystalline material with a parallel (homogeneous), perpendicular (homotropic) or tilted preferred orientation, frequently, orientation layers are disposed between a substrate having conductor tracks and the switchable liquid crystalline material. Polarizers may be arranged in front of and behind the display cell, for example in such a way that they are crossed and do not transmit light. Such a display device is described in, for example, European Patent Application EP-A1-0264667. A display device cannot only operate through rotation of the polarization direction of transmitted or reflected light but also through selective light scattering as described in, for example, U.S. Pat. No. 4,688,900.
In the manufacture of the known display devices care must be taken that no electric fields are formed between oppositely located conductive layers at locations where the formation of an image is not desired. This can be achieved by means of the design of the electrode pattern and the associated conductor tracks running to contact points on the periphery of the device or by means of a device in which the pixels are electrically driven at different instants. Due to this, the possibility of displaying picture elements is limited or use must be made of a complicated electric drive.